ATM communication system with high speed connection-less service function

Abstract

ATM communication system capable of realizing a high speed and efficient datagram delivery for the connection-less communication among the terminals in the ATM network. In the system formed by a plurality of ATM networks inter-networking with each other, each network containing a plurality of terminals, the ATM networks with connection-less service function units for managing a connection-less datagram transmission are provided in the ATM networks, and the connection-less datagram transmission from each terminal to a destination terminal is performed by resolving a connection identifier for identifying an ATM connection connected to a destination side connection-less service function unit associated with a destination side ATM network containing the destination terminal, and transmitting datagram from said each terminal to the destination side connection-less service function unit through the ATM connection identified by the resolved connection identifier.

What is claimed is: 
     
       1. An ATM communication system, comprising: a plurality of ATM networks inter-networking with each other, containing a plurality of terminals and the ATM networks including a first ATM network having connection-less service function means for managing a connection-less datagram transmission in the ATM networks, and a second ATM network having no connection-less service function means;   inter-networking means for inter-networking the first and second ATM networks; and   connection set up means for setting up a first ATM connection between the connection-less service function means of the first ATM network and the inter-networking means, and a second ATM connection between the inter-networking means and a terminal belonging to the second ATM network;   wherein the inter-networking means directly connects the first and second ATM connections set up by the connection set up means at an ATM layer, and the connection-less service function means of the first ATM network is assigned with an address data indicating that said connection-less service function means logically belongs to the second ATM network at a network layer, such that the connection-less datagram transmission from said terminal belonging to the second ATM network is performed by using said address data through the first and second ATM connections connected at the ATM layer.   
     
     
       2. The system of claim 1, wherein the connection-less service function means operates according to a routing protocol for controlling a routing of the datagram to be transmitted between the connection-less service function means and the terminals of the ATM networks. 
     
     
       3. The system of claim 2, wherein the inter-networking means passes routing data used for the routing of the datagram between the first and second ATM networks without terminating a transmission of the routing data. 
     
     
       4. The system of claim 1, wherein the ATM networks further including at least one additional ATM network connected between the first and second ATM networks by the inter-networking means, and the inter-networking means directly connects the first and second ATM connections set up by the connection set up means at an ATM layer through the additional ATM network. 
     
     
       5. The system of claim 4, wherein said at least one additional ATM network has another connection-less service function means, the connection set up means also sets up an additional ATM connection between said another connection-less service function means of the additional ATM network and the inter-networking means, the inter-networking means directly connects the additional and second ATM connections set up by the connection set up means at an ATM layer, and the additional connection-less service function means of the additional ATM network is also assigned with the address data indicating that said connection-less service function means logically belongs to the second ATM network and a network layer, such that the connection-less datagram transmission from said terminal belonging to the second ATM network is performed by using said address data through a selected one of the first and second ATM connections connected at the ATM layer and the additional and second ATM connections connected at the ATM layer. 
     
     
       6. The system of claim 1, wherein the connection set up means sets up the first ATM connection between the connection-less service function means of the first ATM network and the inter-networking means for each one of said plurality of terminals belonging to the first ATM network, and a plurality of first ATM connections for said plurality of terminals belonging to the first ATM network are bundled together into one VP. 
     
     
       7. The system of claim 1, wherein the second ATM connection set up by the connection set up means is connected with a broadcast channel in the second ATM network. 
     
     
       8. An ATM communication system, comprising: a plurality of ATM networks inter-networking with each other, each ATM network containing a plurality of terminals and the ATM networks including a first ATM network having connection-less service function means for managing a connection-less datagram transmission in the ATM networks, and second and third ATM networks having no connection-less service function means;   first inter-networking means for inter-networking the first and second ATM networks;   second inter-networking means for inter-networking the second and third ATM networks; and   connection set up means for setting up a first ATM connection between the connection-less service function means of the first ATM network and the first inter-networking means, a second ATM connection between the first inter-networking means and the second inter-networking means, and a third ATM connection between the second inter-networking means and a terminal belonging to the third ATM network;   wherein the first and second inter-networking means directly connects the first, second, and third ATM connections set up by the connection set up means at an ATM layer, and the connection-less service function means of the first ATM network is assigned with an address data indicating that said connection-less service function means logically belongs to the third ATM network at a network layer, such that the connection-less datagram transmission from said terminal belonging to the third ATM network is performed by using said address data through the first, second, and third ATM connections connected at the ATM layer.   
     
     
       9. The system of claim 8, wherein the connection-less service function means operates according to a routing protocol for controlling a routing of the datagram to be transmitted between the connection-less service function means and the terminals of the ATM networks. 
     
     
       10. The system of claim 9, wherein the first and second inter-netWorking means pass routing data used for the routing of the datagram among the first, second, and third ATM networks without terminating a transmission of the routing data. 
     
     
       11. A method of ATM communication in an ATM communication system formed by a plurality of ATM networks inter-networking with each other, each ATM network containing a plurality of terminals and the ATM networks including a first ATM network having connection-less service function means for managing a connection-less datagram transmission in the ATM networks, and a second ATM network having no connection-less service function means, the method comprising the steps of: inter-networking the first and second ATM networks by first inter-networking means;   setting up a first ATM connection between the connection-less service function means of the first ATM network and the inter-networking means, and a second ATM connection between the inter-networking means and a terminal belonging to the second ATM network:   directly connecting the first and second ATM connections at an ATM layer by the inter-networking means; and   assigning the connection-less service function means of the first ATM network with an address data indicating that said connection-less service function means logically belongs to the second ATM network at a network layer, such that the connection-less datagram transmission from said terminal belonging to the second ATM network is performed by using said address data through the first and second ATM connections connected at the ATM layer.   
     
     
       12. A method of ATM communication in an ATM communication system formed by a plurality of ATM networks inter-networking with each other, each ATM network containing a plurality of terminals and the ATM networks including a first ATM network having connection-less service function means for managing a connection-less datagram transmission in the ATM networks, and second and third ATM networks having no connection-less service function means, the method comprising the steps of: inter-networking the first and second ATM networks by first inter-networking means, and the second and third ATM networks by second inter-networking means;   setting up a first ATM connection between the connection-less service function means of the first ATM network and the first inter-networking means, a second ATM connection between the first inter-networking means and the second inter-networking means, and a third ATM connection between the second inter-networking means and a terminal belonging to the third ATM network;   directly connecting the first, second, and third ATM connections at an ATM layer by the first and second inter-networking means; and   assigning the connection-less service function means of the first ATM network with an address data indicating that said connection-less service function means logically belongs to the third ATM network at a network layer, such that the connection-less datagram transmission from said terminal belonging to the third ATM network is performed by using said address data through the first, second, and third ATM connections connected at the ATM layer.